Tool/software:
BQ24610 - Low Side FET and IC Damage during Battery Transition
Dear TI Support,
We are currently developing a system using the BQ24610 battery charger IC and have encountered a critical issue. During the transition from charging mode to battery-powered mode, the system consistently fails due to damage to the Low Side FET (currently using CSD18543Q3Q) and the BQ24610 IC itself. The battery voltage used in our application is 18V.
In one instance, we also observed burn marks on the current sensing resistor. These failures have occurred repeatedly and are blocking our progress toward mass production.
From our analysis and reference to the datasheet, we suspect this issue may relate to the synchronous rectification behavior in DCM mode, where a brief 80ns LOW SIDE FET turn-on can cause negative inductor current and voltage overshoots, potentially damaging the IC or associated components.
To address this, we are considering the addition of input RC filters, TVS diodes for VCC protection, and re-evaluating the layout. However, we would appreciate your expert advice on the following:
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Recommended protection techniques to prevent such damage.
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Whether our choice of Low Side FET is suitable under these conditions.
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Layout guidelines or proven reference designs that mitigate these issues.
As our production deadline is approaching, we would also like to ask if it's possible to arrange a conference call or on-site technical support for further discussion.
Looking forward to your prompt response.
